10 Be exposure age dating of Late Quaternary relative sea level changes and deglaciation of W Jura and NE Islay, Scottish Inner Hebrides
ABSTRACT New 10 Be exposure age dating and geomorphological mapping of emerged shoreline features in W Jura and NE Islay throw new light on the regional pattern of ice sheet deglaciation and late-glacial relative sea level change. We conclude that the oldest and highest emerged shorelines in this ar...
Published in: | Earth and Environmental Science Transactions of the Royal Society of Edinburgh |
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Cambridge University Press (CUP)
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Online Access: | http://dx.doi.org/10.1017/s175569102200010x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S175569102200010X |
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crcambridgeupr:10.1017/s175569102200010x 2023-05-15T16:40:30+02:00 10 Be exposure age dating of Late Quaternary relative sea level changes and deglaciation of W Jura and NE Islay, Scottish Inner Hebrides DAWSON, Alastair G. BISHOP, Paul HANSOM, James FABEL, Derek Natural Environment Research Council 2022 http://dx.doi.org/10.1017/s175569102200010x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S175569102200010X en eng Cambridge University Press (CUP) https://creativecommons.org/licenses/by/4.0/ CC-BY Earth and Environmental Science Transactions of the Royal Society of Edinburgh volume 113, issue 3, page 253-266 ISSN 1755-6910 1755-6929 General Earth and Planetary Sciences General Environmental Science journal-article 2022 crcambridgeupr https://doi.org/10.1017/s175569102200010x 2023-01-20T07:08:42Z ABSTRACT New 10 Be exposure age dating and geomorphological mapping of emerged shoreline features in W Jura and NE Islay throw new light on the regional pattern of ice sheet deglaciation and late-glacial relative sea level change. We conclude that the oldest and highest emerged shorelines in this area were produced ~15.7–16.3 ka, shortly after ice sheet deglaciation ~16.5 ka. It is envisaged that the first incursion of marine waters into coastal areas took place close to a former ice sheet margin that oscillated in position across this part of the Scottish Inner Hebrides. The first evidence of late-glacial marine sedimentation following deglaciation consists of emerged marine terrace fragments and unvegetated gravel beach ridges, the former represented by a prominent glacio-isostatically tilted shoreline that declines in altitude NE to SW, from ~40 m above ordnance datum (OD) in NW Jura to ~19 m OD in central Islay. In W Jura, north of Loch Tarbert, spectacular staircases of up to 55 unvegetated gravel beach ridges were formed shortly after regional deglaciation, possibly within 1 ka. A preliminary estimate of the average rate of relative sea level lowering across W Jura between deglaciation and the Younger Dryas is in the order of ~7 mmyr −1 . Geomorphological evidence from Shian Bay, W Jura, indicates a truncation of the late-glacial beach ridge staircases by a large 480-m-long beach ridge (the Colonsay Ridge) at ~14.9 ka, when former relative sea level was at ~18 m OD. This ridge may represent the product of either a stillstand in the progressive lowering of relative sea level during the late-glacial or a reversal. This raises the intriguing possibility of an association between ridge formation and the timing of the well-established global meltwater pulse 1A between ~14.65 and ~14.8 ka. Article in Journal/Newspaper Ice Sheet Cambridge University Press (via Crossref) Islay ENVELOPE(59.717,59.717,-67.350,-67.350) Jura ENVELOPE(13.501,13.501,68.062,68.062) Long Beach Earth and Environmental Science Transactions of the Royal Society of Edinburgh 1 14 |
institution |
Open Polar |
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Cambridge University Press (via Crossref) |
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English |
topic |
General Earth and Planetary Sciences General Environmental Science |
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General Earth and Planetary Sciences General Environmental Science DAWSON, Alastair G. BISHOP, Paul HANSOM, James FABEL, Derek 10 Be exposure age dating of Late Quaternary relative sea level changes and deglaciation of W Jura and NE Islay, Scottish Inner Hebrides |
topic_facet |
General Earth and Planetary Sciences General Environmental Science |
description |
ABSTRACT New 10 Be exposure age dating and geomorphological mapping of emerged shoreline features in W Jura and NE Islay throw new light on the regional pattern of ice sheet deglaciation and late-glacial relative sea level change. We conclude that the oldest and highest emerged shorelines in this area were produced ~15.7–16.3 ka, shortly after ice sheet deglaciation ~16.5 ka. It is envisaged that the first incursion of marine waters into coastal areas took place close to a former ice sheet margin that oscillated in position across this part of the Scottish Inner Hebrides. The first evidence of late-glacial marine sedimentation following deglaciation consists of emerged marine terrace fragments and unvegetated gravel beach ridges, the former represented by a prominent glacio-isostatically tilted shoreline that declines in altitude NE to SW, from ~40 m above ordnance datum (OD) in NW Jura to ~19 m OD in central Islay. In W Jura, north of Loch Tarbert, spectacular staircases of up to 55 unvegetated gravel beach ridges were formed shortly after regional deglaciation, possibly within 1 ka. A preliminary estimate of the average rate of relative sea level lowering across W Jura between deglaciation and the Younger Dryas is in the order of ~7 mmyr −1 . Geomorphological evidence from Shian Bay, W Jura, indicates a truncation of the late-glacial beach ridge staircases by a large 480-m-long beach ridge (the Colonsay Ridge) at ~14.9 ka, when former relative sea level was at ~18 m OD. This ridge may represent the product of either a stillstand in the progressive lowering of relative sea level during the late-glacial or a reversal. This raises the intriguing possibility of an association between ridge formation and the timing of the well-established global meltwater pulse 1A between ~14.65 and ~14.8 ka. |
author2 |
Natural Environment Research Council |
format |
Article in Journal/Newspaper |
author |
DAWSON, Alastair G. BISHOP, Paul HANSOM, James FABEL, Derek |
author_facet |
DAWSON, Alastair G. BISHOP, Paul HANSOM, James FABEL, Derek |
author_sort |
DAWSON, Alastair G. |
title |
10 Be exposure age dating of Late Quaternary relative sea level changes and deglaciation of W Jura and NE Islay, Scottish Inner Hebrides |
title_short |
10 Be exposure age dating of Late Quaternary relative sea level changes and deglaciation of W Jura and NE Islay, Scottish Inner Hebrides |
title_full |
10 Be exposure age dating of Late Quaternary relative sea level changes and deglaciation of W Jura and NE Islay, Scottish Inner Hebrides |
title_fullStr |
10 Be exposure age dating of Late Quaternary relative sea level changes and deglaciation of W Jura and NE Islay, Scottish Inner Hebrides |
title_full_unstemmed |
10 Be exposure age dating of Late Quaternary relative sea level changes and deglaciation of W Jura and NE Islay, Scottish Inner Hebrides |
title_sort |
10 be exposure age dating of late quaternary relative sea level changes and deglaciation of w jura and ne islay, scottish inner hebrides |
publisher |
Cambridge University Press (CUP) |
publishDate |
2022 |
url |
http://dx.doi.org/10.1017/s175569102200010x https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S175569102200010X |
long_lat |
ENVELOPE(59.717,59.717,-67.350,-67.350) ENVELOPE(13.501,13.501,68.062,68.062) |
geographic |
Islay Jura Long Beach |
geographic_facet |
Islay Jura Long Beach |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
Earth and Environmental Science Transactions of the Royal Society of Edinburgh volume 113, issue 3, page 253-266 ISSN 1755-6910 1755-6929 |
op_rights |
https://creativecommons.org/licenses/by/4.0/ |
op_rightsnorm |
CC-BY |
op_doi |
https://doi.org/10.1017/s175569102200010x |
container_title |
Earth and Environmental Science Transactions of the Royal Society of Edinburgh |
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1 |
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14 |
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1766030897002315776 |